References considered to be relevant as background to the presently disclosed subject matter are listed below:    [1] Francois A, Milliat F, Guipaud O, Benderitter M. Inflammation and immunity in radiation damage to the gut mucosa. Biomed Res Int.; 2013:123241.    [2] Arad G, Levy R, Hillman D, Kaempfer R. Superantigen antagonist protects against lethal shock and defines a new domain for T-cell activation. Nat Med. 2000; 6:414-21.    [3] Arad G, Levy R, Nasie I, Hillman D, Rotfogel Z, Barash U, et al. Binding of Superantigen Toxins into the CD28 Homodimer Interface Is Essential for Induction of Cytokine Genes That Mediate Lethal Shock. PLoS Biol. 2011. page e1001149.    [4] Ramachandran G, Tulapurkar M E, Harris K M, Arad G, Shirvan A, Shemesh R, et al. A peptide antagonist of CD28 signaling attenuates toxic shock and necrotizing soft-tissue infection induced by Streptococcus pyogenes. J Infect Dis. 2013; 207:1869-77.    [5] Kaempfer R, Arad G, Levy R, Hillman D, Nasie I, Rotfogel Z. CD28: Direct and Critical Receptor for Superantigen Toxins. Toxins (Basel). 2013; 5:1531-42.    [6] Petersen C, Baumann M, Petersen S. New targets for the modulation of radiation response-selective inhibition of the enzyme cyclooxygenase 2. Curr Med Chem Anticancer Agents. 2003; 3:354-9.    [7] Bulger E, Maier R, Sperry J, Joshi M, Henry S, Moore F A, et al. A novel drug for treatment of necrotizing soft tissue infections: Results of a Phase 2a randomized controlled trial of AB103, a CD28 co-stimulatory receptor antagonist. JAMA J Am Med Assoc Surg. 2014; 149, 528-536.    [8] WO 2013/108193.    [9] Srinivasan M, Gienapp I E, Stuckman S S, Rogers C J, Jewell S D, Kaumaya P T, Whitacre C C. (2002) Suppression of experimental autoimmune encephalomyelitis using peptide mimics of CD28. J Immunol. 169:2180-2188.    [10] Kapsogeorgou, E. K., Moutsopoulos, H. M. & Manoussakis, M. N. A novel B7-2 (CD86) splice variant with a putative negative regulatory role. J. Immunol. 180, 3815-3823 (2008).    [11] Evans, J. E. et al. Nat Immun (2005) 6:271-279.    [12] Schwartz J C et al. Nature (2201) 410:604-608
Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.